Electronics_For_You_July_2017

Do-it-yourself

120 July 2017 | ElEctronics For you http://www.EFymag.com

Voting Machine

Using AVR Microcontroller

Ankush AggArwAl

S.C.

Dwive

Di

P

olling by electronic voting

machines (EVMs) has become

a norm during elections.

Unlike paper ballot systems, EVMs

are safe and reliable as these rule

out the possibility of invalid voting.

These are more economical and ef-

ficient too. Their compact size saves

transportation costs.

Here we describe the design of

an electronic voting machine based

on ATmega16A microcontroller. To

cast a vote, users

need to press the key

against the name of

the candidate of their

choice. The vote is

automatically saved

in the microcontroller,

and simultaneously

the LCD shows the

message “Thank You.”

The author’s prototype

is shown in Fig. 1.

Circuit and working

As shown in Fig. 2, the circuit of the

electronic voting machine is built around

ATmega16A microcontroller (IC2), IC

7805 (IC1), a 16×2 LCD (LCD1) and

other associated components.

The controller used here operates off

5V DC supply. So a 7805 voltage regula-

tor IC is used to step 9V DC down to 5V.

Capacitors C1 and C2 are used to reduce

ripples. ATmega16A has 32 general

purpose input/output (I/O) pins. An ex-

ternal 8MHz crystal oscillator is used to

provide the timing pulse. Four switches

(S1 through S4) are connected to Port B

(PB0, PB1, PB2 and PB3) of IC2.

The LCD (LCD1) operates in 4-bit

1

2

IC1 3

7805

C2

10u

16V

CON1

FOR 9V

C1

100u

XTAL1

C3 8MHz

22p

C4

22p

(^1) PB0
Vcc
10
(^2) PB1
(^3) PB2
(^4) PB3
(^5) PB4
(^6) PB5
(^7) PB6
(^8) PB7
(^9) RST
(^15) (TXD)PD1
(^14) (RXD)PD0
(^21) PD7
(^20) PD6
(^19) PD5
(^18) PD4
(^17) PD3
(^16) PD2
XTAL2
13
XTAL1
12
(^11) GND
PA0^40
PA1^39
PA2^38
PA4^36
PA5^35
PA6^34
PA7^33
AREF
32
AVCC^30
GND^31
PC7^29
PC6^28
PC5^27
PC4^26
PC3^25
PC2^24
PC1^23
PC0^22
PA3^37
IC2
ATMEGA16A
25V
S5
RESET
R10
10K
R3
R2
R5
R4
S1
S2
S3
S4
LED2
R7
LED3
R8
LED4
R9
4
RS
5
R/W
6
EN
7
D0
8
D1
9
D2
10
D3
11
D4
12
D5
13
D6
14
D7
1 Vss
3 VO
2 VDD A/VEE 15
LCD1 K 16
16X2 LCD
VR1
10K
GND
LED5
POWER
R1
220E
LED1
R6
R2 − R5 = 10K
R6 − R9 = 220E
S1 = FOR FIRST PARTY i.e. AAP
S2 = FOR SECOND PARTY i.e. KKK
S3 = FOR THIRD PARTY i.e BJP
S4 = FOR RESULT
D5 = FOR RESET
Fig. 1: Author’s prototype
Fig. 2: Circuit diagram of the electronic voting machine using ATmega16A microcontroller